Devices for distributing or spreading particulate material historically comprise a hopper for holding the material and a mechanically driven distributing mechanism. In cases where a compact and easily portable device is preferable, a hand-held material spreader is commonly used, in which case the distributing mechanism is typically driven by a hand crank and the device includes a grip or handle for carrying and orienting it.
More sophisticated hand-held devices comprise an auxiliary power source thereby reducing fatigue of a user, freeing one of the user's hands and typically improving the uniformity of the material distribution.
Devices such as these are described in U.S. Pat. No. 3,993,225 (Manni), U.S. Pat. No. 5,409,166 and U.S. Pat. No. 5,119,993 (Gunzel Jr. et al) and U.S. Pat. No. 6,425,500 (McNally).
U.S. Pat. No. 3,993,225 discloses an operator carryable unitary assembly for distributing a particulate material from a front end thereof. The assembly has a housing for enclosing a drive, the housing including a handle, a cylindrical distribution chamber with a vertical axis and a slot directed away from the handle. A motor is mounted below the distribution chamber to rotate a rotor within the chamber, the rotor having vanes spaced from the center of the rotor. A hopper is removably mounted to the top of the distribution chamber. A control means is provided on the handle adjacent the side toward the distribution chamber for controlling the motor, and for controlling the flow of particulate material from the hopper into the distribution chamber.
U.S. Pat. No. 5,409,166 discloses a portable electric-powered particulate spreader with a housing having an inlet and an outlet. A reservoir for holding particulate material is located above the housing and a handle for holding the spreader is located behind the housing. A blower is located with a flow path extending from the inlet to the outlet for inducing air flow along the flow path. A particulate intake port is formed in a channel wall which encompasses an exhaust channel extending downstream from the blower to the outlet. A valve controls flow of particulate material from the reservoir to the particulate intake port. An agitator located between the reservoir and exhaust channel rotationally reciprocates and induces vibrations which assist the flow of particulate material. A foil in the exhaust channel produces a low static pressure which tends to draw particulate material from the reservoir into the air flow. Delays are built in so that the blower turns on before opening the valve is opened and the valve is closed before the blower is turned off. U.S. Pat. No. 5,119,993 discloses a similar material spreader.
U.S. Pat. No. 6,425,500 discloses a portable device for dispensing a particulate salt material upon a ground surface having a body with a substantially hollow interior, a forwardly located and open dispensing end and a reclosable end cap engaged with a rearwardly located end for permitting the hollow interior to be filled holding a volume of the particulate material. A rotor element is mounted in communication with the first open end and includes a plurality of individual and arcuately arrayed dispensing portions arranged around a central cross wise extending and rotatable shaft. A driving mechanism is associated with the body for actuating the rotor element to dispense volumes of the held particulate and may include either a hand-operated crank or an electric motor operatively connected to the rotatable shaft and powered by at least one battery contained within the hollow interior of the body and electrically communicable with the motor.